HR: 1330h
AN: PP32B-0293    [PDF]
TI: Assessment of Modern Climate Baselines for Paleoclimatic Reconstructions and Model Testing in North America
AU: * Shafer, S L
EM: sshafer@usgs.gov
AF: U.S. Geological Survey, Earth Surface Processes Team 200 SW 35th Street, Corvallis, OR 97333 United States
AU: Bartlein, P J
EM: bartlein@uoregon.edu
AF: University of Oregon, Department of Geography, Eugene, OR 97403 United States
AU: Anderson, K H
EM: katherine.anderson@colorado.edu
AF: University of Colorado, INSTAAR 1560 30th Street, Boulder, CO 80309 United States
AU: Thompson, R S
EM: rthompson@usgs.gov
AF: U.S. Geological Survey, Earth Surface Processes Team Box 25046, MS980 Denver Federal Center, Denver, CO 80225 United States
AB: Paleoclimatologic studies usually employ a "modern" climatic data set as the baseline against which to measure the differences between past climates and those of today. Weather records for the past century indicate that climate has not been stationary, and thus the selection of the baseline time-interval from the past hundred years will affect the interpreted paleoclimatic results. In addition, the spatial resolution of the baseline data set, coupled with the manner in which elevation is considered, may also affect these results. Our work thus far has employed a 1951-1980 climatic baseline on a 25-km equal-area grid of North America for which climatic variables have been interpolated from the records of approximately 8000 climate stations (Bartlein and Lipsitz, 1994). We compare reconstructions using the 25-km equal-area data set with reconstructions using a higher resolution 10-km equal-area data set of climatic variables interpolated from the Climate Research Unit (East Anglia, UK; Mitchell et al., 2003) 30-minute TS 2.0 data set. This 10-km data set provides coverage for the 20th century and thus permits the assessment of the effects of using different baseline time-intervals on paleoclimatic reconstructions and model validation exercises. Although the continental-scale patterns are similar among the 25-km data set and the various 10-km data sets, there are measurable differences, especially in regard to moisture variables, in the past and present climate reconstructions generated using these different climate baselines.
DE: 1699 General or miscellaneous
DE: 4215 Climate and interannual variability (3309)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2003 Fall Meeting